Organic el display unit, method of manufacturing the same, and electronic apparatus

ABSTRACT

An organic EL display unit includes a first substrate, a second substrate, a display layer, and a sealing section. The display layer is provided between the first substrate and the second substrate. The display layer includes an organic layer. The sealing section is provided continuously from an end surface of the display layer to at least a portion of respective end surfaces of the first substrate and the second substrate.

TECHNICAL FIELD

The present disclosure relates to an organic electroluminescence (EL)display unit that emits light utilizing an organic EL phenomenon, amethod of manufacturing the organic EL display unit, and an electronicapparatus including the organic EL display unit.

BACKGROUND ART

Small-sized to mid-sized display units used for portable devices such assmartphones and tablet terminals have been requested to have ahigh-definition display performance with low power consumption and tohave a thin and light-weight design property. As the display units thatmeet these requests, a display unit with use of an organiclight-emitting device (OLED), i.e., an organic EL display unit hasattracted attentions. The organic EL display unit is a self-luminousdisplay unit, and thus has a wide viewing angle and does not necessitatea backlight. Therefore, the organic EL display unit has features such aslow power consumption, responsiveness, and decrease in thickness of thedisplay unit itself, compared with a display unit with use of liquidcrystal.

Further, the small-sized to mid-sized display units have been requestedto enlarge an effective display region as a measure to seek the designproperty, and thus have been requested to narrow the width of aso-called bezel portion (frame portion) on the periphery of the displayregion (i.e., narrow bezel has been requested).

The narrow bezel has also been requested in large-sized display units.For the large-sized display units, developments of ultra-multi-pixeldisplays such as 4K2K displays and 8K4K displays have been under way.Ultra-large-sized displays having a size of 100 inches or more, forexample, have been increasingly demanded, because pixel roughness isless likely to be noticeable even when the display region is increasedin size. Such ultra-large-sized displays may be achieved bymanufacturing an ultra-large-sized display panel through combination ofa plurality of display panels in terms of the number and the yield ofthe ultra-large-sized displays, and the cost. In this case, reduction inthe bezel region of the display panels to be combined is requested.

In contrast, the organic EL display unit includes, as a light-emittingdevice, an organic EL device made of a material containing an organicmaterial. In the organic EL device, layers containing an organicmaterial (organic layers) such as a hole injection layer, alight-emitting layer, and an electron injection layer are stackedbetween an anode and a cathode. The organic layers react easily withmoisture and oxygen in the atmosphere, and are deteriorated. Thedeteriorated organic layer decreases performances as the light-emittingdevice, such as decrease in light emission luminance and unstable lightemission.

PTL 1 and PTL 2 disclose, as methods for preventing entering of, forexample, moisture and oxygen into the organic layer, an organic EL unitin which a region from an emission region to a side surface thereof iscovered with a gas barrier layer (or a barrier film) made of aninorganic material.

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Patent Application Publication No.2009-117079

PTL 2: Japanese Unexamined Patent Application Publication No.2003-282241

SUMMARY OF INVENTION

In the above-mentioned organic EL units, however, an organic layer forflattening irregularities is provided below the gas barrier layer. Thegas barrier layer covers the organic layer to thereby prevent enteringof moisture from the outside. Here, the organic layer is formed by amethod such as a spin coating method and an organic chemical vapordeposition (CVD) method, and thus there is a portion which runs off tothe periphery of the emission region. This makes it difficult to narrowthe bezel region, because it is necessary for the gas barrier layer thatcovers the organic layer to be formed larger than the run-off portion ofthe organic layer.

It is therefore desirable to provide an organic EL display unit thatmakes it possible to achieve a narrow bezel while keeping reliability, amethod of manufacturing the organic EL display unit, and an electronicapparatus.

An organic EL display unit according to an embodiment of the presentdisclosure includes a first substrate, a second substrate, a displaylayer including an organic layer provided between the first substrateand the second substrate, and a sealing section provided continuouslyfrom an end surface of the display layer to at least a portion ofrespective end surfaces of the first substrate and the second substrate.

A method of manufacturing an organic EL display unit according to anembodiment of the present disclosure includes forming a display layerincluding an organic layer on a first substrate, joining the firstsubstrate and a second substrate together, with the display layer beingdisposed therebetween, and forming a sealing section continuously froman end surface of the display layer to at least a portion of respectiveend surfaces of the first substrate and the second substrate.

An electronic apparatus according to an embodiment of the presentdisclosure includes the organic EL display unit according to the presentdisclosure.

According to the organic EL display unit, the method of manufacturingthe organic EL display unit, and the electronic apparatus of therespective embodiments of the present disclosure, there is provided, onthe end surface of the display layer including the organic layerprovided between the first substrate and the second substrate, thesealing section that is formed continuously from the end surface of thedisplay layer to at least a portion of the respective end surface of thefirst substrate and the second substrate. This thereby reduces the areaof a peripheral region provided on the periphery of the display regionwhile preventing entering of moisture into the organic layer, comparedwith a common organic EL display unit with a sealing structure providedbetween substrates.

According to the organic EL display unit, the method of manufacturingthe organic EL display unit, and the electronic apparatus of therespective embodiments of the present disclosure, there is provided, onthe end surface of the display layer including the organic layerprovided between the first substrate and the second substrate, a sealingsection that has an overlapping portion at at least a portion of therespective end surfaces of the first substrate and the second substrate.This reduces the area of the peripheral region provided on the peripheryof the display region while preventing entering of moisture into theorganic layer, compared with a common organic EL display unit with asealing structure provided between substrates. Thus, it becomes possibleto provide the organic EL display unit that has a narrow bezel regionwhile keeping reliability and the electronic apparatus including theorganic EL display unit. It is to be noted that the effects describedherein are not necessarily limitative, and may be any effects describedin the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view of a configuration of a display unitaccording to an embodiment of the present disclosure.

FIG. 2 is a plan view of an overall configuration of the display unitillustrated in FIG. 1.

FIG. 3 illustrates an example of a pixel drive circuit illustrated inFIG. 2.

FIG. 4 is an explanatory schematic view of an entering path of moisturein a sealing section of an embodiment of the present disclosure.

FIG. 5 is a flowchart illustrating an example of steps for manufacturingthe display unit illustrated in FIG. 1.

FIG. 6A is an explanatory schematic view of an example of a dividingmethod.

FIG. 6B is a schematic view of a state subsequent to that illustrated inFIG. 6A.

FIG. 7 is a characteristic diagram in which characteristics of dividedsurfaces are compared which are formed by the dividing methodillustrated in FIGS. 6A and 6B.

FIG. 8A is an explanatory schematic view of another example of thedividing method.

FIG. 8B is an explanatory schematic view of the dividing method in astate subsequent to that illustrated in FIG. 8A.

FIG. 8C is an explanatory schematic view of the dividing method in astate subsequent to that illustrated in FIG. 8B.

FIG. 9 is a plan view of an overall configuration of a display unitaccording to Modification Example 1 of the present disclosure.

FIG. 10 is a cross-sectional view of an example of a cross-sectionalconfiguration of the display unit illustrated in FIG. 9.

FIG. 11 is a cross-sectional view of another example of thecross-sectional configuration of the display unit illustrated in FIG. 9.

FIG. 12 is a cross-sectional view of a display unit according toModification Example 2 of the present disclosure.

FIG. 13 is an explanatory schematic view of one of steps formanufacturing a display unit according to Modification Example 3 of thepresent disclosure.

FIG. 14 is a further explanatory schematic view of one of themanufacturing steps illustrated in FIG. 13.

FIG. 15 is a perspective view of an outer appearance of ApplicationExample 1 with use of the display unit of the present disclosure.

FIG. 16 is a perspective view of an outer appearance of ApplicationExample 2.

FIG. 17A is a perspective view of an example of an outer appearance ofApplication Example 3.

FIG. 17B is a perspective view of another example of an outer appearanceof Application Example 3.

DESCRIPTION OF EMBODIMENTS

Some embodiments of the disclosure are described in detail below in thefollowing order with reference to drawings.

1. Embodiment (A display unit having a sealing section on an end surfaceof a display panel)

1-1. Overall Configuration

1-2. Manufacturing Method

1-3. Function and Effect

2. Modification Example

Modification Example 1 (A display unit having a terminal section at aside of a display panel)

Modification Example 2 (A display unit having a wiring line on a rearsurface of a substrate)

Modification Example 3 (A dividing method in a step for a massproduction of a display panel)

3. Application Example (An application example to an electronicapparatus)

1. Embodiment (1-1. Overall Configuration)

FIG. 1 illustrates a cross-sectional configuration of an organic ELdisplay unit (display unit 1) according to an embodiment of the presentdisclosure. The display unit 1 is used as an organic EL television, forexample. The display unit 1 includes a drive substrate 11 on which thereare provided a display region 110A and a peripheral region 110B on theperiphery of the display region 110A (see FIG. 2). The display unit 1is, for example, a top surface emission (so-called top emission) displayunit. The top surface emission display unit uses, as light-emittingdevices, an organic EL device 10 that emits any of color light beams ofR (red), G (green), and B (blue) (a red organic EL device 10R, a greenorganic EL device 10G, a blue organic EL device 10B), and the colorlight beams are emitted from top surface side (side opposite to thedrive substrate 11). The display unit 1 according to the presentembodiment includes a display layer 20 that configures the organic ELdevice 10, and the drive substrate 11 and a counter substrate 31provided to face each other with the display layer 20 being interposedtherebetween. The display layer 20, the drive substrate 11, and thecounter substrate 31 configure a display panel P. A sealing section 50that covers at least the display layer 20 is provided on an end surfaceof the display panel P.

FIG. 2 illustrates an example of an overall configuration of the displayunit 1 illustrated in FIG. 1. In the display region 110A, there aredisposed a plurality of pixels 5 (red pixels 5R, green pixels 5G, andblue pixels 5B) in matrix. Further, a signal line drive circuit 120 anda scanning line drive circuit 130 which are drivers for displaying animage are provided in the peripheral region 110B positioned on theperiphery (on outer edge side, or on outer peripheral side) of thedisplay region 110A.

A pixel drive circuit 140 is provided inside the display region 110A.FIG. 3 illustrates an example of the pixel drive circuit 140 (an exampleof pixel circuits of the red pixels 5R, the green pixels 5G, and theblue pixels 5B). The pixel drive circuit 140 is an active drive circuitprovided below a pixel electrode 26 described later. The pixel drivecircuit 140 includes a drive transistor Tr1, a write transistor Tr2, acapacitor (a holding capacitor) Cs located between these transistors Tr1and Tr2. The pixel drive circuit 140 also includes the organic EL device10 coupled in series to the drive transistor Tr1 between a first powersupply line (Vcc) and a second power supply line (GND). In other words,the organic EL device 10 is provided in each of the red pixels 5R, thegreen pixels 5G, and the blue pixels 5B. Each of the drive transistorTr1 and the write transistor Tr2 is configured by a typical thin filmtransistor (TFT), and may have, for example, an inverted staggeredstructure (a so-called bottom gate type) or a staggered structure (a topgate type); the configuration thereof is not particularly limited.

In the pixel drive circuit 140, a plurality of signal lines 120A arearranged in a column direction, and a plurality of scanning lines 130Aare arranged in a row direction. An intersection of each of the signallines 120A and each of the scanning lines 130A corresponds to one of thered pixel 5R, the green pixel 5G, and the blue pixel 5B. Each of thesignal lines 120A is coupled to the signal line drive circuit 120, andan image signal is supplied from the signal line drive circuit 120 to asource electrode of the write transistor Tr2 through the signal line120A. Each of the scanning lines 130A is coupled to the scanning linedrive circuit 130, and a scanning signal is sequentially supplied fromthe scanning line drive circuit 130 to a gate electrode of the writetransistor Tr2 through the scanning line 130A.

In the display unit 1 of the present embodiment, the sealing section 50is provided on the end surface of the display panel P including thedisplay layer 20 between the drive substrate 11 and the countersubstrate 31 as described above. The sealing section 50 is provided forsuppressing entering of moisture into the display layer 20 (morespecifically, an organic layer 28); the sealing section 50 maypreferably cover at least the display layer 20 of the display panel P.More preferably, an end of the sealing section 50 may be so provided asto overlap a portion of respective end surfaces of the drive substrate11 and the counter substrate 31 being in contact with the display layer20.

While the sealing section 50 that is formed of only an inorganic film 51made of an inorganic material is able to suppress the entering ofmoisture into the display layer 20 (more specifically, organic layer28), a layered structure of the inorganic film 51 and an organic film 52is able to suppress the entering of moisture into the display layer 20even more. Table 1 summarizes calculations of moisture vaportransmission rate by measuring corrosiveness of calcium in Samples 1 to3 prepared as described below. It is to be noted that the measuringcondition of the corrosiveness of calcium was set such that temperaturewas 60° C. and humidity was 90% (relative humidity). Sample 1 is a filmsubstrate (polyethylene naphthalate (PEN) substrate; having a thicknessof 100 μm) on which a calcium (Ca) film is formed, with a PEN substratebeing joined thereto. Sample 2 includes a filling layer provided on a Cafilm, with a UV-cured resin film with a thickness of 3 μm, for example,and an inorganic film (an aluminum oxide (Al₂O₃) film) with a thicknessof 25 nm, for example, being formed in this order on the filling layer.Sample 3 further includes a UV-cured resin film and an Al₂O₃ film beingstacked in addition to the configuration of Sample 2.

TABLE 1 Moisture Vapor Transmission Configuration Rate (g/m²/day) Sample1 Film Substrate (PEN) 6.0E Sample 2 PEN/Filling Layer/UV-Cured 6.9E−3Resin Film/Al₂O₃ Film Sample 3 PEN/Filling Layer/UV-Cured 5.9E−5 ResinFilm/Al₂O₃ Film/ UV-Cured Resin Film/Al₂O₃ Film

It is appreciated from Table 1 that configuring the sealing section 50by the layered structure of the inorganic film 51 and the organic film52 enables the effect of suppressing the entering of moisture into thedisplay layer 20 to be enhanced. Further, it is appreciated thatproviding the layered films of the inorganic film 51 and the organicfilm 52 in a stacked manner enables the suppressing effect to be furtherenhanced. This is because of the film property of the inorganic film 51.There is a concern that the inorganic film 51 may cause a minute flawdue to dust that may attach thereto in the middle of film formation ordue to a defect during the film formation. The dust attached during thefilm formation or the flaw may be the cause of the entering of moisturefrom the outside. Therefore, formation of the organic film 52 on thesurface of the inorganic film 51 makes it possible to cover the dust andto prevent the flaw of the inorganic film 51, thus delaying the enteringof moisture into the display layer 20.

The sealing section 50 may preferably have a multi-layered structure inwhich two or more layered films each configured by the inorganic film 51and the organic film 52 being stacked. FIG. 4 schematically illustratesan entering path of moisture H in a portion of the configuration of thesealing section 50 in the display unit illustrated in FIG. 1. Forexample, even when a flaw is formed in each of the inorganic films 51Band 51C as illustrated in FIG. 4, a diffusion rate of the moisture Hhaving entered the inorganic film 51C through the flaw is suppressed dueto a maze effect in which the moisture H passes through the organic film52B provided therebetween to reach a flaw of the inorganic film 51B. Inthis manner, stacking the inorganic film 51 and the organic film 52alternately makes it possible to suppress the diffusion rate of themoisture H efficiently. More specifically, for example, three layers ofthe inorganic film 51 and three layers of the organic film 52 may bepreferably formed; in other words, an inorganic film 51A, an organicfilm 52A, an inorganic film 51B, an organic film 52B, an inorganic film51C, and an organic film 52C may be preferably formed from the endsurface of the display panel P as illustrated in FIG. 1. Thefilm-formation width of the outermost organic film 52C may be preferablysubstantially the same as the film thickness (hereinafter, referred tosimply as “thickness”) of the display panel P in the Y-axis direction.More specifically, the film-formation width of the outermost organicfilm 52C may be preferably set such that the end surfaces of the organicfilm 52C in the Y-axis direction reach respective surfaces (surface ofthe drive substrate 11 and surface of the counter substrate 31 oppositeto the facing surface thereof) of the display panel P as illustrated inFIG. 1.

The material of the inorganic film 51 may be desirably aluminum oxide(Al₂O₃), for example. Other examples of the material of the inorganicfilm 51 may include silicon oxide (SiO₂), zirconium oxide (ZrO₂),titanium oxide (TiO₂), zinc oxide (ZnO₂), indium-zinc oxide (IZO),indium-tin oxide (ITO), indium-gallium-zinc oxide (IGZO), aluminum-zincoxide (AZO), gallium-zinc oxide (GZO), silicon nitride (SiN), andsilicon oxynitride (SiON). Further, a metal film made of a metal such asaluminum (Al) and titanium (Ti) may also be adopted. It is preferable touse one or more of these materials for formation of the inorganic film51. In addition, a common material for a wiring line may also be usedfor the formation thereof. More specific examples of the common wiringline material may include ruthenium (R), platinum (Pt), iridium (Ir),palladium (Pd), rhodium (Rh), gold (Au), silver (Ag), copper (Cu),nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), tantalum (Ta),tungsten (W), molybdenum (Mo), titanium (Ti), aluminum (Al), silicon(Si), germanium (Ge), and zinc (Zn). One or more of these materials oran alloy thereof may also be used for the formation. Examples ofavailable film-forming method for the inorganic film 51 may include asol-gel method, a sputtering method, a vacuum vapor deposition method, achemical vapor deposition (CVD) method, and an atomic layer depositionmethod (ALD; HYPERLINK “javascript: void (0)”). In particular, the ALDmethod may be preferably used for the film formation, and the filmthickness (thickness) thereof may be preferably equal to or more than 10nm and equal to or less than 200 nm.

As the material of the organic film 52, a material having good adhesion(affinity) to the inorganic film 51 may be preferable in order toenhance a sealing property of the sealing section 50. More specificexamples of the material of the organic film 52 may include a curedresin composition containing a cycloalkane structure-containingpolymerizable compound or a high-acid value phthalic acidstructure-containing polymerizable compound.

When the sealing section 50 has a multi-layered structure in which thelayered films of the inorganic film 51 and the organic film 52 arestacked as described above, it is desirable that end surfaces of theorganic films (organic films 52A and 52B of the organic film 52illustrated in FIG. 1) formed on end surface side may not be exposed tothe outside. The organic film does not have a sufficientmoisture-sealing capacity. Accordingly, when the end surface of theorganic film formed near the end surface of the display panel P isexposed to the outside, the end surface of the organic film results inserving as the entering path of moisture into the display layer 20.Therefore, in the sealing section 50 having the multi-layered structureof the inorganic film 51 and the organic film 52, the inorganic film 51formed on the organic film 52 is requested to cover the whole of theunderlying organic film 52 so as to be blocked from the outside. Inother words, the film-formation width (D) of the organic film 52 may bepreferably greater gradually in the order of the film formation. Morespecifically, the film-formation width of the organic films 52A, 52B,and 52C that configure the sealing section 50 as illustrated in FIG. 1may preferably have a relationship of respective widths D1, D2, and D3,in which D1 is less than D2 and D2 is less than D3 (D1<D2<D3).

The thickness of the organic film 52 may be preferably as thin aspossible. This is because the bezel region of the display unit 1 issubstantially determined by the thickness of the organic film 52, sinceit is possible to form the inorganic film 51 to be much thinner than theorganic film 52. However, the organic film 52 has a role of suppressingthe diffusion rate of moisture when the inorganic film 52 has a flaw asdescribed above. Further, the outermost organic film 52 (organic film52C) functions as a protective film of the inorganic film 51 (inorganicfilm 51C). Therefore, the organic film 52 may preferably have athickness of equal to or more than 3 μm and equal to or less than 30 μm,for example.

As a method of forming such an organic film 52, a method is contemplatedin which, for example, a liquid organic agent may be applied and cured.This makes it possible to fill minute irregularities formed on theinorganic film 52 without gap. It is to be noted that the liquid organicagent may preferably have lowered viscosity for use in order toeffectively utilize a capillary phenomenon thereof, for example.Examples of the specific film-forming method may include a dispensingmethod in which a liquid organic agent is dispensed with an air pressureor a mechanical pressure, an inkjet method, and an offset method.

The dispensing method enables the application width to be more slenderand thinner by narrowing the distance between a nozzle and anapplication surface with use of a slender nozzle. Thus, the applicationwidth may be set depending on a nozzle size and an applicationcondition, which brings high general-purpose properties. The inkjetmethod enables the application amount per drop to be a micro amount,thus making it possible to control the film-formation width and thethickness precisely. The offset method involves immersing an offsetcomponent in a liquid agent and transferring the offset component to anapplication section. The offset method brings the offset component intodirect contact with the application section, and thus has difficulty inbeing applied to film formations of a second layer and subsequentlayers. However, by making the width of the offset component thinner andby quantifying the amount of the liquid agent for immersion, it becomespossible to form an organic film having stable film-formation width andthickness, which enables the productivity to be enhanced. It is to benoted that examples of the application method limited to the secondlayer and subsequent layers may include a dip method.

Bringing the offset component into contact with an application surfaceat an angle makes it possible to reduce dispersion in the applicationwidth and the thickness, while reducing an influence caused by thecontact. In addition, vacuum may also be used in the applicationprocess.

The present embodiment describes an example of the sealing section 50having a configuration in which the inorganic film 51A is formeddirectly on the end surface of the display panel P, with the organicfilm 52A, the inorganic film 51B, the organic film 52B, the inorganicfilm 51C, and the organic film 52C are stacked in this order on theinorganic film 51A. However, when the surface of the end surface of thedisplay panel P is rough, for example, an unillustrated flattening filmcontaining an organic material may also be formed, as an underlayer, onthe surface of the end surface. The flattening film fills the minuteirregularities of the end surface of the display panel P without gap,thereby making it possible to stabilize the film properties of theinorganic film 51 and the organic film 52 to be formed thereafter and tosuppress the thicknesses thereof to the minimum. Examples of the methodof forming the flattening film may include a method in which a liquidorganic agent is applied and cured for film formation similarly to theabove-described method of forming the organic film 52.

Hereinafter, respective components that configure the display panel Pare described. As described above, the display panel P includes thedrive substrate 11 and the counter substrate 31 that are disposed toface each other with the display layer 20 being interposed therebetween.The display layer 20 is configured by a semiconductor section 20A and adisplay section 20B. A transistor 20X that drives each of the organic ELdevices 10R, 10G, and 10B is provided in the semiconductor section 20A.The organic EL devices 10R, 10G, and 10B are provided in the displaysection 20B. It is to be noted that, in the present embodiment, thedrive substrate 11 and the counter substrate 31 have a complete solidstructure in which the entire surfaces thereof are joined together withan adhesive layer 40.

The drive substrate 11 is a supporting body with a main surface side onwhich the organic EL devices 10 of respective colors (red organic ELdevice 10R, green organic EL device 10G, and blue organic EL device 10B)are formed in an array. Examples of an available substrate for the drivesubstrate 11 may include quartz and glass; a substrate made of a plasticsuch as polyether sulfone, polycarbonate, polyimides, polyamides,polyacetals, polyethylene terephthalate, polyethylene naphthalate,polyethylene ether ketone, and polyolefins; a metal foil substrate madeof a metal such as aluminum (Al), nickel (Ni), copper (Cu), andstainless steel having undergone a surface insulating treatment; andpaper. A buffer layer for enhancing adhesion and flatness or afunctional film such as a barrier film for enhancing a gas barrierproperty may also be formed on the above-described substrate. Further,when it is possible to form a channel layer 22 without heating the drivesubstrate 11 by methods such as a sputtering method, it is also possibleto use an inexpensive plastic film as the drive substrate 11.

The transistor Tr1 for driving and the transistor Tr2 for writing andvarious wiring lines are provided in the semiconductor section 20A onthe drive substrate 11. A flattening insulating film 25 is provided onthe transistors Tr1 and Tr2 and the wiring lines. While the transistorsTr1 and Tr2 (hereinafter, referred to as a thin film transistor 20X) maybe either a top gate type or a bottom gate type, the thin filmtransistor 20X of a top gate type is used for description in thisexample. The thin film transistor 20X has a configuration in which apair of source/drain electrodes (a source electrode 21A and a drainelectrode 21B), the channel layer 22, a gate insulating film 23, and agate electrode 24 are provided in this order from drive substrate 11side, with the flattening insulating film 25 that flattens thesemiconductor section 20A being further provided.

The source electrode 21A and the drain electrode 21B are provided apartfrom each other, and are electrically coupled to the channel layer 22. Ametal material and a semi-metal or inorganic semiconductor material maybe used as the material forming the source electrode 21A and the drainelectrode 21B. Specific examples of the material may include a metalsimple substance such as platinum (Pt), titanium (Ti), ruthenium (Ru),molybdenum (Mo), copper (Cu), tungsten (W), nickel (Ni), aluminum (Al),gold (Au), silver (Ag), and tantalum (Ta); and an alloy thereof. Otherexamples thereof may include indium-tin oxide (ITO) and molybdenum oxide(MoO). The source electrode 21A and the drain electrode 21B are made ofany of the metal simple substances or an alloy thereof a monolayerthereof or two or more layers thereof may also be stacked for use.Examples of the layered structure may include layered structures ofTi/Al/Ti and Mo/Al. Further, the wiring line 27A may also have aconfiguration similar to those of the source electrode 21A and the drainelectrode 21B.

The channel layer 22 is provided in an island shape between the sourceelectrode 21A and the drain electrode 21B, and has a channel region at aposition facing the gate electrode 24 described later. The channel layer22 may have a thickness of 5 nm to 100 nm, for example. The channellayer 22 may be made of, for example, an organic semiconductor materialsuch as a peri-Xanthenoxanthene (PXX) derivative. Examples of theorganic semiconductor material may include polythiophene,poly-3-hexylthiophene (P3HT) in which a hexyl group is introduced intopolythiophene pentacene[2,3,6,7-dibenzoanthracene], polyanthracene,naphthacene, hexacene, heptacene, dibenzopentacene, tetrabenzopentacene,chrysene, perylene, coronene, Terrylene, ovalene, quoterrylene,circumanthracene, benzopyrene, dibenzopyrene, triphenylene, polypyrrole,polyaniline, polyacetylene, polydiacetylene, polyphenylene, polyfuran,polyindole, polyvinyl carbazole, polyselenophene, polytellurophene,polyisothianaphthene, polycarbazole, polyphenylene sulfide,polyphenylene vinylene, polyphenylene sulfide, polyvinylene sulfide,polythienylene vinylene, polynaphthalene, polypyrene, polyazulene,phthalocyanines represented by copper phthalocyanine, merocyanine,hemicyanine, polyethylene dioxythiophene, pyridazine, naphthalenetetracarboxylic acid diimide,poly(3,4-ethylendioxythiophene)/polystyrenesulfonic acid (PEDOT/PSS),4,4′-biphenyldithiole (BPDT), 4,4′-diisocyanobiphenyl,4,4′-diisocyano-p-terphenyl,2,5-bis(5′-thioacetyl-2′-thiophenyl)thiophene,2,5-bis(5′-thioacetoxyl-2′-thiophenyl)thiophene, 4,4′-diisocyanophenyl,benzidine (biphenyl-4-4′-diamine), TCNQ (tetracyanoquinodimethane),charge-transfer complexes represented by a tetrathiafulvalene (TTF)-TCNQcomplex, a bisethylenetetrathiafulvalene (BEDTTTF)-perchloric acidcomplex, a BEDTTTF-iodine complex, and a TCNQ-iodine complex,biphenyl-4,4′-dicarboxylic acid,24-di(4-thiophenylacetylinyl)-2-ethylbenzene,24-di(4-isocyanophenylacetylinyl)-2-ethylbenzene, dendrimer, fullerenessuch as C60, C70, C76, C78, and C84,24-di(4-thiophenylethynyl)-2-ethylbenzene,2,2″-dihydroxy-1,1′:4′,1″-terphenyl, 4,4′-biphenyldiethanal,4,4′-biphenyldiol, 4,4′-biphenyldisocyanate, 24-diacetylbenzene,diethylbiphenyl-4,4′-dicarboxylate,benzo[22-c;3,4-c′;5,6-c″]tris[22]dithiol-24,7-trithion, α-sexithiophene,tetrathiotetracene, tetraselenotetracene, tetratelluric tetracene,poly(3-alkyl thiophene), poly(3-thiophene-(3-ethanesulfonic acid),poly(N-alkylpyrrole)poly(3-alkylpyrrole), poly(3,4-dialkylpyrrole),poly(2,2′-thienylpyrrole), and poly(dibenzothiophene sulfide), andquinacridone. In addition, it is also possible to use a compoundselected from the group consisting of condensed polycyclic aromaticcompounds, porphyrin derivatives, phenyl vinylidene-based conjugatedoligomers, and thiophene-based conjugated oligomers. Further, a mixtureof an organic semiconductor material and an insulating polymer materialmay also be used.

The channel layer 22 may be formed using the vacuum vapor depositionmethod; however, for example, the above-mentioned material may bepreferably dissolved in an organic solvent, for example, to be used asan ink solution in application/printing process to form the channellayer 22. This is because the application/printing process allows forcost reduction compared with the vacuum vapor deposition method and iseffective for enhancement of throughput. Specific examples of theapplication/printing process may include methods such as cast coating,spin coating, spray coating, inkjet printing, relief printing, flexoprinting, screen printing, gravure printing, and gravure offsetprinting.

The gate insulating film 23 is provided within a thickness range of, forexample, 50 nm to 1 μm both inclusive between the channel layer 22 andthe gate electrode 24. The gate insulating film 23 may be formed by aninsulating film containing one or more of silicon oxide (SiO), siliconnitride (SiN), silicon oxynitride (SiON), hafnium oxide (HfO), aluminumoxide (AlO), aluminum nitride (AlN), tantalum oxide (TaO), zirconiumoxide (ZrO), hafnium oxynitride, hafnium-silicon oxynitride, aluminumoxynitride, tantalum oxynitride, and zirconium oxynitride, for example.The gate insulating film 23 may have either a monolayer structure, or alayered structure, for example, using two or more materials such as anSiN film and an SiO film. When the gate insulating film 23 has thelayered structure, it is possible to improve interface properties withrespect to the channel layer 22 and to effectively suppress mixing ofimpurities (e.g., moisture) into the channel layer 22 from the outside.The gate insulating film 23 is formed by application, and thereafter ispatterned into a predetermined shape with etching. Depending on amaterial, the pattern formation may be performed by a printing techniquesuch as inkjet printing, screen printing, offset printing, and gravureprinting.

The gate electrode 24 has a role of applying a gate voltage to the thinfilm transistor 20X to control carrier density in the channel layer 22with the gate voltage. The gate electrode 24 is provided in a selectiveregion on the drive substrate 11, and may be made of, for example, ametal simple substance such as platinum (Pt), titanium (Ti), ruthenium(Ru), molybdenum (Mo), copper (Cu), tungsten (W), nickel (Ni), aluminum(Al), and tantalum (Ta), or an alloy thereof. Alternatively, two or morethereof may also be stacked for use.

The flattening insulating film 25 is provided for preventing a shortcircuit between respective wiring lines (source electrode 21A and drainelectrode 21B, channel layer 22, or gate electrode 24), and forflattening the surface of the drive substrate 11 on which the thin filmtransistor 20X is provided. Examples of the material for forming theflattening insulating film 25 may include polyimide-based,polyacrylate-based, epoxy-based, cresol novolak-based orpolystyrene-based, polyamide-based, and fluorine-based organicinsulating materials; and inorganic materials such SiO.

The display section 20B includes the light-emitting device 10, and isprovided on the semiconductor section 20A, more specifically, on theflattening insulating film 25. The light-emitting device 10 is alight-emitting device in which the pixel electrode 26 as an anode, apartition wall 27, the organic layer 28 including a light-emitting layer28B, and a counter electrode 29 as a cathode are stacked in this orderfrom semiconductor section 20A side. The counter substrate 31 is joinedonto the counter electrode 29 with the adhesive layer 40 being providedtherebetween. The thin film transistor 20X and the light-emitting device10 are electrically coupled to the pixel electrode 26 through aconnection hole 25A provided in the flattening insulating film 25.

The pixel electrode 26 also serves as a reflection layer; it isdesirable to have as high reflectance as possible in order to enhanceemission efficiency. In particular, when using the pixel electrode 26 asan anode, it is desirable that the pixel electrode 26 may be made of amaterial having a high hole injection property. Examples of the materialof the pixel electrode 26 may include a metal simple substance such asaluminum (Al), chromium (Cr), gold (Au), platinum (Pt), nickel (Ni),copper (Cu), tungsten (W), and silver (Ag), and an alloy thereof. Atransparent electrode, which has a large work function, may preferablybe stacked on the surface of the pixel electrode 26.

The partition wall 27 is provided for securing an insulating propertywith respect to the pixel electrode 26 and the counter electrode 29 andfor forming an emission region into a desired shape. The partition wall27 is made of a photosensitive resin, for example. The partition wall 27is provided only around the pixel electrode 26, and a region, exposedfrom the partition wall 27, of the pixel electrode 26 serves as theemission region. It is to be noted that, while the organic layer 28 andthe counter electrode 29 are provided also on the partition wall 27,only the emission region generates light emission.

The organic layer 28 has a configuration in which, for example, a holesupply layer 28A (hole injection layer 28A1, hole transport layer 28A2),the light-emitting layer 28B, and an electron supply layer 28C (electrontransport layer 28C1, electron injection layer 28C2) are stacked inorder from pixel electrode 26 side. It is sufficient for these layers tobe provided as necessary. The layers that form the organic layer 28 mayhave different configurations from each other depending on, for example,emission colors of the organic EL devices 10R, 10G, and 10B. The holeinjection layer 28A1 is provided for enhancing hole injectionefficiency, and also serves as a buffer layer that prevents a leak. Thehole transport layer 28A2 is provided for enhancing efficiency oftransporting holes to the light-emitting layer. The light-emitting layer28B performs application of an electric field to cause recombination ofelectrons and holes, thus emitting light. The organic EL devices 10R,10G, and 10B includes, respectively, light emitting-layers 28BR, 28BG,and 28BB that emit corresponding color light beams. The electrontransport layer 28C1 is provided for enhancing efficiency oftransporting electrons to the light-emitting layer 28B. The electroninjection layer 28C2 is provided for enhancing electron injectionefficiency.

The counter electrode 29 is formed of any of alloys of aluminum (Al),magnesium (Mg), calcium (Ca), and sodium (Na), for example. Among thealloys, an alloy of magnesium and silver (Mg—Ag alloy) may be preferablebecause it has both electrical conductivity and low absorbability in athin film. The ratio of magnesium to silver in the Mg—Ag alloy is notparticularly limited; however, the film thickness ratio of magnesium tosilver may be preferably within a range of Mg:Ag=20:11 to 1:1. Further,the material of the counter electrode 29 may also be an alloy ofaluminum (Al) and lithium (Li) (Al—Li alloy).

A protective film 30 is provided on the counter electrode 29 so as tocover the end surfaces of the organic layer 28 and the counter electrode29, for example. The protective film 30 may be made of, for example, aninorganic material such as silicon oxide (SiO_(x)), silicon nitride(SiN_(x)), silicon nitride oxide (SiN_(x)O_(y)), titanium oxide(TiO_(x)), and aluminum oxide (Al_(x)O_(y)).

The adhesive layer 40 is provided substantially uniformly on theprotective film 30, and joins the drive substrate 11 on which thedisplay layer 20 is provided to the counter substrate 31. The adhesivelayer 40 may be made of, for example, an epoxy resin or an acrylicresin. Further, a sheet-like resin film may also be used to form theadhesive layer 40. Moreover, the adhesive layer 40 may not benecessarily provided; for example, the adhesive layer 40 may be providedonly in the peripheral region 110B to allow the display region 110A tohave a hollow portion.

The counter substrate 31 seals the organic EL device 10 together withthe adhesive layer 40. The counter electrode 31 is made of a materialsuch as glass that is transparent to each of color light beams emittedfrom the organic EL devices 10R, 10G, and 10B. On the surface of thecounter substrate 31 on the drive substrate 11 side, unillustrated colorfilters configured of, for example, a red filter, a green filter, and ablue filter are provided, respectively, at positions corresponding tothe organic EL devices 10R, 10G, and 10B, for example. An unillustratedblack matrix is provided among the respective organic EL devices 10R,10G, and 10B.

(1-2. Manufacturing Method)

The display unit 1 may be manufactured, for example, in accordance withthe flowchart illustrated in FIG. 5.

The semiconductor section 20A is formed on the drive substrate 11 (StepS101). First, metal films to be the source electrode 21A and the drainelectrode 21B are formed on the entire surface of the drive substrate 11using the sputtering method or the vacuum vapor deposition method, forexample. Next, the metal films are patterned using photolithography andetching, for example, to thereby form the source electrode 21A and thedrain electrode 21B. Thereafter, the channel layer 22 and the gateinsulating film 23 are formed in order between the source electrode 21Aand the drain electrode 21B. More specifically, an organic semiconductormaterial, for example, a peri-Xanthenoxanthene (PXX) compound solutionis applied. Thereafter, the applied organic semiconductor material isheated to form the channel layer 22, following which a spin coatingmethod is used to apply the above-mentioned gate insulating filmmaterial, for example, a polyvinylpyrrolidone (PVP) solution is appliedand dried. This allows the gate insulating layer 23 to be formed.

Next, the flattening insulating film 25 is formed on the respectivewiring lines (source electrode 21A and drain electrode 21B, channellayer 22, or gate electrode 24) and the drive substrate 11. Morespecifically, for example, a photosensitive resin such as polyimide isapplied, and a flattened layer 28 is patterned into a predeterminedshape by means of exposure and development. In addition, the connectionhole 25A is formed and calcined.

Next, the display section 20B is formed (Step S102). First, the pixelelectrode 26 is formed on the flattening insulating film 25. Morespecifically, a metal film made of, for example, aluminum(Al)/indium-tin oxide (ITO) is formed on the flattening insulating film25 by the sputtering method, for example. Thereafter, a metal film at apredetermined position is selectively removed by wet etching, forexample, to form the pixel electrodes 26 separated for the respectiveorganic EL devices 10R, 10G, and 10B. Thereafter, the partition wall 27is formed between the respective pixel electrodes 26, following whichthe organic layer 28 including the light-emitting layer 28B is formedusing a deposition method, for example. The counter electrode 29 isformed on the organic layer 28 using the sputtering method, for example.Next, the protective film 30 made of the above-mentioned material isformed on the counter electrode 29 using a plasma chemical vapordeposition (plasma CVD) method, a physical vapor deposition (PVD)method, and an atomic layer deposition (ALD) method, and the depositionmethod, for example.

Next, the drive substrate 11 and the counter substrate 31 are joinedtogether (Step S103). First, the color filters and the black matrix areformed on the counter substrate 31 made of the above-mentioned materialthrough, for example, application by means of the spin coating methodand subsequent patterning using the photolithography method. Thereafter,the adhesive layer 40 made of the above-mentioned material is formed onthe counter substrate 31, following which the counter substrate 31 isjoined to the drive substrate 11 with the adhesive layer 40 beinginterposed therebetween to complete the display panel P.

Thereafter, division of the display panel P is performed (Step S104). Inorder to achieve a display unit having as narrow a bezel region(peripheral region 110B) as possible as in the display unit 1 accordingto the disclosure, it is necessary to precisely divide the drivesubstrate 11, display layer 20, and the counter substrate 31, with theadhesive layer 40 being included therein.

Scribing division using a mechanical wheel is typically applied todivision of a brittle material. The scribing division involves, forexample, forming a crevice on the surface of a glass substrate andextending the crevice. However, it is difficult to control a directionin which the crevice is extended; it is not possible to secure precisionin the division due to, for example, extension of a crevice in adiagonal direction during the division. Therefore, it is necessary forthe peripheral region 110B to have a certain room as a margin for thedivision, which prevents a bezel to be narrow.

In contrast, in the present embodiment, for example, a division methodusing dicing (FIGS. 6A and 6B), or a grinding treatment after thescribing division (FIG. 8C) is performed to achieve a narrow bezel. Useof any of these methods makes it possible to precisely divide thedisplay panel P, as in the display unit 1, having a very short distancefrom a position of the division to the display region 110A in which thelight-emitting device 10 is provided, without occurrence of, forexample, any burr, chip, or crack on the end surface of the displaypanel P, in particular, on the end surfaces of the drive substrate 11and the counter substrate 31.

The dicing is a method that involves rotating a solid abrasive grain(blade B) at high speed as illustrated in FIG. 6A to divide a substrate(display panel P in this example) as illustrated in FIG. 6B. Use of thedicing for the division of the display panel P makes it possible tolimit a surface roughness of a division surface, i.e., a surfaceroughness of the end surface to 1 μm or smaller.

In the division using the dicing, cooing water is typically used to coolequipment, to remove chip powder generated by the division, and toprevent abrasion of the abrasive grain. FIG. 7 illustrates results ofmeasurement, by calcium corrosion test, of the influence of water usedduring the dicing division. First, a polyimide material was applied ontoa glass substrate by the spin coating method such that the polyimidematerial had a thickness of about 1 μm, following which a calcium (Ca)film was formed by deposition at a center portion of the appliedpolyimide material. Silicon nitride (SiN) was formed as a barrier filmon the Ca film by the chemical vapor deposition (CVD) method.Thereafter, a UV-cured epoxy resin was applied to a counter glasssubstrate, which was joined to the glass substrate to prepare Sample 4.In Sample 4, when moisture was permeated to reach the Ca film, the Cafilm was corroded, and was converted to calcium hydroxide to be changedinto transparent. Further, the SiN film formed on the upper surface ofthe Ca film served to protect the upper surface of the Ca film; thecorrosion due to the entering of moisture was limited only to corrosionfrom the end surface of Sample 4 formed by joining the glass substratestogether.

Four sides near the Ca film of Sample 4 was divided by dicing processingusing cooling water, following which baking was performed for 1 hour invacuum. Subsequently, Sample 4 was stored in a dry atmosphere at a dewpoint of −75° C. together with Sample 5 not having been subjected to thedicing processing as a comparative example, and thereafter stored in athermostat bath of a temperature of 60° C. and a humidity of 90% tocompare the corrosion states of Ca.

As appreciated from FIG. 7, Sample 4 having been subjected to the dicingprocessing had less Ca corrosion than unprocessed Sample 5. It wasappreciated from this result that exposure of the display panel P,having been subjected to the dicing processing, to cooling water is noproblem as long as a material having a sealing property is used as theadhesive layer 40 and as long as the exposure is performed for a shortperiod of time by performing a vacuum baking treatment after thedivision.

Moreover, the scribing and the grinding treatment thereafter aredescribed. As described above, it is difficult to control an extendingdirection of the crevice formed by the scribing on the surface of theglass substrate. In particular, in a structure having a resin layer(adhesive layer 40) between two glass substrates (drive substrate 11 andcounter substrate 31) as in the display panel P, it is very difficult tosufficiently extend a crevice formed on the surface of the substrate ina thickness direction.

Therefore, in the present embodiment, for example, the adhesive layer 40near a portion to be divided is removed by laser processing (UV laser L)before forming a crevice in the counter substrate 31 as illustrated inFIG. 8A. Thereafter, a scribing blade C is used to form a crevice on thesurface of the display panel P, and the crevice is extended to dividethe display panel P as illustrated in FIG. 8B. Thereafter, the dividedsurface is cut in an arrow direction by mechanical processing asillustrated in FIG. 8C. More specifically, a sheet with a solid abrasivegrain adhered thereto (abrasive sheet S) is pressed against the dividedsurface, and is moved in an oscillating manner in the arrow direction,for example, to grind the divided surface, thus enabling the surfaceroughness of the end surface to be limited to 1 μm or smaller.

Next, the sealing section 50 is formed on the end surface of the displaypanel P (Step S105). First, a description is given of a case of formingan aluminum oxide (Al₂O₃) film as the inorganic film 51A using theatomic layer deposition (ALD) method. The inorganic film 51A is formedby the ALD method using, for example, trimethyl aluminum (TMA; (CH₃)₃Al)as a first precursor gas, and, for example, water (H₂O) as a secondprecursor gas, with a nitrogen gas or an argon gas being used as a purgegas. The temperature for the film formation may be desirably 120° C. orlower, and more desirably 100° C. or lower.

Subsequently, the organic film 52A is formed using, for example, theUV-cured epoxy resin by means of an offset application method, forexample. In this case, the viscosity of the organic agent before curingmay be preferably 50 mPa·s or lower, for example. Specific film-formingmethod involves using a stainless steel jig having a transfer sectionsize of 0.1 mm width as an offset jig, for example. A method forattaching the organic agent involves the following procedures. Forexample, a transfer surface of the offset jig is immersed in the organicagent, that is leveled to have a set thickness (e.g., 10 μm to 30 μm)using an applicator, in a parallel manner, and the immersed transfersurface of the offset jig is pulled up in a parallel manner. Thereafter,the reference plane of a panel-fixing jig and the reference plane of theoffset jig are made closer in a parallel manner, and pressed againsteach other to transfer the organic agent to a panel application surface.At this time, in order to spread the organic agent, a time period ofthree seconds, for example, may be necessary to hold this state,following which the reference plane of the panel-fixing jig and thereference plane of the offset jig are released from each other in aparallel manner. In this case, in order to eliminate the influence ofdamage, due to a contact, to the inorganic layer that covers an exposedsurface of the cross-sectional structure of the panel, it is preferableto use an offset component having a larger width than that of theexposed surface and to bring the offset component into contact with theapplication surface at an angle of 5°, for example.

Examples other than the above-described offset method may include thedispensing method. Application conditions may involve, for example,using a nozzle having an external diameter of 0.23 mm and an internaldiameter of 0.1 mm, and performing application such that: the distancefrom a nozzle tip to the application surface is 30 μm; the nozzlemovement speed is 50 mm/sec.; and the application pressure is 0.015 MPa.

Using the above-described method, the organic agent is applied, forexample, to the four sides of the display panel P and, as necessary, tofour corners, following which the organic agent is cured. The curingmethod involves ultraviolet (UV) irradiation at a light integral ofabout 700 mJ/cm² or higher, for example. The curing method may bepreferably selected appropriately depending on materials; heat and UVirradiation may be used together. Further, the UV irradiation may alsobe performed, for example, in an inert gas such as the atmosphere,nitrogen, and argon.

Next, a second layered inorganic film (inorganic film 51B) is formedusing a method similar to that for the inorganic film 51A, andthereafter a second layered organic film (organic film 52B) is formed.In this example, the dip method, for example, may be used for filmformation. First, the application surface of the display panel P is madecloser in the longitudinal direction to the organic agent in a bath in aparallel manner to be brought into contact therewith. As for thethickness in the Y-axis direction of the display panel P, theapplication surface is brought into contact with a curved tip, which isformed by utilization of surface tension, of the organic agent, therebypreventing the organic agent from running off to a surface other thanthe panel application surface. The panel application surface is broughtinto contact with the organic agent in this manner, and thereafter ispulled up, for example, at a constant speed of about 5 mm/sec. in aparallel manner to thereby form the organic film 52B. This process isperformed for the four side of the display panel P, following which theUV irradiation is used for curing.

It is to be noted that the dispensing method may also be used as thefilm-forming method for the organic film 52B. Application conditions mayinvolve, for example, using a nozzle having an external diameter of 0.23mm and an internal diameter of 0.1 mm, and performing application suchthat: the distance from a nozzle tip to the application surface is 100μm; the nozzle movement speed is 25 mm/sec.; and the applicationpressure is 0.015 MPa.

Subsequently, methods similar to those for the inorganic film 51B andthe organic film 52B are used, respectively, for formation of a thirdlayered inorganic film 51C and a third layered organic film 52C. Thisallows the sealing section 50 to be formed. Through the above-describedprocedures, the display unit 1 illustrated in FIG. 1 is completed.

(1-3. Function and Effect)

In the display unit 1, a scanning signal is supplied from the scanningline drive circuit 130 to each pixel 5 through the gate electrode of thewrite transistor Tr2, and an image signal is supplied from the signalline drive circuit 120 through the write transistor Tr2 to a holdingcapacitor Cs and is stored therein. In other words, the drive transistorTr1 is on/off controlled depending on the signal stored in the holdingcapacitor Cs. This causes a drive current Id to be injected into theorganic EL device 10, and thus holes and electrons are recombined togenerate light emission. The light is transmitted through the counterelectrode 29, the protective film 30, the adhesive layer 40,unillustrated color filters of respective colors, and the countersubstrate 31 to be extracted, because the display unit 1 is a topsurface emission (top emission) display unit in this example. In amanner as described above, the display unit 1 performs image display(color image display).

Incidentally, an organic EL display unit used, for example, as anorganic EL television is requested to enlarge an effective displayregion as a measure to seek a design property as described above, andthus is requested to reduce a bezel portion. However, simply narrowingthe bezel region causes entering of moisture from the outside, thusdeteriorating organic layers configuring the light-emitting device. Thiscauses a non-emission region referred to as “dark spot” to be formed,which impairs the reliability of the organic EL display unit.

In order to solve this issue, it is necessary, for example, to allow anorganic insulating film such as a flat film provided around the emissionregion and a so-called sealing layer that performs surface-sealing of agap between substrates to have a certain degree of width. Further, anorganic insulating film formed to have a relatively large size forsuppressing entering of, for example, moisture from the outside causesmoisture remaining in the film to be increased accordingly. Thus, it iscontemplated that formation of a separating groove that separates theorganic insulating film into an inner peripheral portion and an outerperipheral portion suppresses entering of moisture contained in theorganic insulating film.

However, it is difficult for the above-described method to reduce thebezel region sifnificantly, although the method is able to prevent orsuppress the entering of moisture into the organic layer.

In contrast, unlike the example of providing a structure that suppressesthe entering of moisture into the peripheral region 110B on theperiphery of the display region 110A, the display unit 1 of the presentembodiment is configured to provide the sealing structure 50 on the endsurface of the display panel formed by joining the drive substrate 11and the counter substrate 31 together, with the display layer 20including the organic EL device 10 being interposed therebetween. Inparticular, by configuring the sealing structure 50 as layered films ofthe inorganic film 51 made of an inorganic material and the organic film52 made of an organic material, it becomes possible to minimize thesealing structure that suppresses the entering of moisture into thedisplay layer 20. This enables the bezel region to be 0.1 mm or smaller,for example.

In the present embodiment, the sealing section 50 is provided on the endsurface of the display layer 20 including the organic layer 28 providedbetween the drive substrate 11 and the drive substrate 11 as describedabove. The sealing section 50 is so provided as to overlap at least aportion of the end surfaces of the drive substrate 11 and the drivesubstrate 11. This makes it possible to prevent the entering of moistureinto the organic layer 28 while reducing the peripheral region 110Bprovided on the periphery of the display region 110A as much aspossible. Thus, it becomes possible to provide the display unit 1 thathas a narrow bezel region while keeping reliability, and an electronicapparatus including the display unit 1.

2. Modification Example

Now, modification examples (Modification Examples 1 to 3) of theforegoing embodiment are described. It is to be noted that the samereference numeral is assigned to the same component in the foregoingembodiment, and description therefor is omitted where appropriate.

Modification Example 1

FIG. 9 schematically illustrates a planar configuration of an organic ELdisplay unit (a display unit 2) according to Modification Example 1 ofthe foregoing embodiment. FIG. 10 illustrates a cross-sectionalconfiguration taken along line I-I in FIG. 9. Unlike the display unit 1in which the sealing section 50 is provided continuously across theentire end surface of the display panel P, the organic EL display unit 2is provided with, for example, a wiring line terminal (a terminalsection 150), that drives the organic EL device 10 from the outside, atone side of the peripheral region 110B.

The terminal section 150 is provided with, for example, a wiring linelayer 61 that is formed as the same wiring line layer as theabove-described source electrode 21A and drain electrode 21B. Theflattening insulating film 25 is formed on the wiring line layer 61 inthe manufacturing process; however, the flattening insulating film 25 onthe wiring line layer 61 is removed for electrical coupling to theoutside, and thus the wiring line layer 61 is in a state of beingexposed. The removal process is performed, for example, after theformation of the sealing section 50 in the foregoing embodiment, andthus the sealing section 50 at one side, at which the terminal section150 is provided, of the display panel P results in being removed.Therefore, in the present modification example, a separation groove Athat completely separates the flattening insulating film 25 is providedbetween the display region 110A and the terminal section 150 asillustrated in FIG. 10. The provision of the separation groove A forms anew end surface configured by the display layer 50 and the countersubstrate 31, and a sealing section 50A similar to the sealing section50 in the foregoing display unit 1 is formed on the new end surface.

Further, as illustrated in FIG. 11, on the new end surface configured bythe display layer 50 and the counter substrate 31, the inorganic film 51in direct contact with the end surface is provided continuously from theend surface onto the drive substrate 11 inside the separation groove A.A sealing section 50B may be provided which includes the organic films52 and other inorganic films 51 being alternately layered outside theinorganic film 51. One end surface of each of the organic films 52 andother inorganic films 51 is in contact with the inorganic film 51 on thedrive substrate 11. It is to be noted that FIG. 11 illustrates anexample in which the separation groove A is completely filled with thesealing section 50B; however, there may be a gap between the sealingsection 50B and the flattening insulating film 25A that configures theseparation groove A.

This makes it possible to reduce the bezel region as much as possiblewhile preventing the entering of moisture into the organic layer 28,also in the display unit 2 including, at one side of the peripheralregion 110B, the terminal section 150 that drives the organic EL device10 from the outside. In particular, the provision of the sealing section50B having the structure illustrated in FIG. 11 makes it possible tosuppress the entering of moisture through a gap between the drivesubstrate 11 and the flattening insulating film 25 and thus to furtherprevent the entering of moisture into the organic layer 28.

Modification Example 2

FIG. 12 illustrates a cross-sectional configuration of an organic ELdisplay unit (a display unit 3) according to Modification Example 2 ofthe foregoing embodiment. The display unit 3 has a configuration inwhich the wiring line of the transistor 20X and the cathode electrode ofthe organic EL device 10 are taken out toward a rear surface of thedrive substrate 11. This configuration may be used, for example, as amethod of taking out a wiring line of a display panel circumferentiallysurrounded by another display panel when manufacturing anultra-large-sized display panel by combining a plurality of displaypanels as described above.

As for a specific method of taking out each wiring line, for example,when a wiring line of the transistor 20X is taken out toward the rearsurface of the drive substrate 11, a through-silicon via (TSV) thatpasses through the drive substrate 11 may be provided to take out thewiring line toward the rear surface to electrically couple the wiringline to an external drive circuit. In contrast, when taking out acathode electrode toward the rear surface of the drive substrate 11, anelectrically conductive film may be formed between the end surface ofthe display panel P and a sealing section 70 provided on the end surfacethereof. Alternatively, as illustrated in FIG. 12, an inorganic film 71Athat configures the sealing section 70 may be made of an inorganicmaterial having electrical conductivity (e.g., an atomic layerdeposition (ALD) film of zinc oxide (ZnO) and aluminum (Al)). In thiscase, by extending the inorganic film 71A from the end surface to therear surface of the drive substrate 11, it becomes possible to take outthe cathode electrode toward the rear surface through the end surface ofthe display panel.

It is to be noted that the film formation of the ZnO-based electricallyconductive film by the atomic layer deposition (ALD) method may beperformed, for example, at a low temperature around 100° C. using zincdiethyl ((C₂H₃)₂Zn) and water. The specific resistance for a ZnOmonolayer prepared at 110° C. is 2×10−2Ω. cm. In order to lower thespecific resistance, Al is doped into ZnO (i.e, ZnO:Al (AZO)). When thedoping of Al is performed by the ALD method, trimethyl aluminum (TMA)and water are used in a manner similar to the Al₂O₃ film. For example,when 20 ZnO layers are stacked as 20 atomic layers by means of the ALDmethod, and one Al₂O₃ layer is interlayered to prepare ZnO (20layers)/Al₂O₃ (1 layer), there is a possibility that the specificresistance may be on the order of 10⁻³Ω.

Modification Example 3

FIG. 13 illustrates a portion of steps for manufacturing a display unit1 according to Modification Example 3 of the foregoing Example. In thepresent modification example, an description is given of a dividingmethod in which a plurality of organic EL devices (display layer 20)that serve as the display panel P are formed on and joined to alarge-sized substrate referred to as a so-called “mother glass”, andthereafter the substrate with the organic EL devices being joinedthereto is divided into display panels P having a predetermined size.

As described above, cutting processing after dicing and scribing may beone of the methods of forming the plurality of organic EL devices on thelarge-sized substrate and thereafter dividing it into the display panelsP having the predetermined size as described above. However, the cuttingprocessing is slower than a typical scribing division in the processingspeed; for example, the speed of the cutting process is a tenth ( 1/10)of the speed of scribing processing, although it depends on the amountof processing, and thus the production efficiency is lowered.

Therefore, in the present modification example, the dividing step isperformed by separating it into two stages. First, as illustrated inFIG. 13A, scribing division is performed as a first cut, in whichdivision speed is fast while division precision is low. Morespecifically, for example, a large-sized glass substrate PL is dividedinto a plurality of display panels PP by scribing along a cut line 1using a laser, after removal of the adhesive layer 40 as illustrated inFIG. 8A. The cut line 1 is configured to allow for scribing divisionsuch that the display panel PP is larger than a predetermined outershape of the organic EL display unit taking into consideration divisionprecision in the scribing division.

Subsequently, as illustrated in FIG. 13B, a second cut is performedwhich involves dividing the display panel PP having been dividedseparately to have a predetermined size by means of precision division.As the dividing method in this case, it is preferable to adoptmechanical cutting processing using dicing or the abrasive sheet S withuse of the solid abrasive grain.

Performing the two-stage division in this manner makes it possible toenhance the production efficiency. Further, even taking intoconsideration a processing facility, it is possible to significantlyreduce the facility cost.

It is to be noted that, when a plurality of display panels P areprepared at once as in the present modification example, forming theabove-described sealing section 50 as described below makes it possibleto further enhance the production efficiency of the display unit 1.

The inorganic film 51 configuring the sealing section 50 is effectivelyformed by the ALD method from the viewpoints of film thickness and afilm property as described above. However, the ALD method is slow in thefilm-forming speed; a time period of 10 hours or more may be sometimesnecessary to form a film having a thickness of 25 nm, for example.Therefore, in the present modification example, it is preferable to joina plurality of display panels P together and to form an inorganic filmat once on the surface thereof. More specifically, the large-sized glasssubstrate PL illustrated in (A) of FIG. 14 is divided separately asillustrated in (B) of FIG. 14 by the above-described two-stage division,and the divided display panels PP are further subjected to the precisiondivision to provide the display panels P having a predetermined size.The display panels P are overlapped on top of each other as illustratedin (C) of FIG. 14, and the inorganic film is formed at once on thesurfaces thereof. This makes it possible to significantly increase thefilm formation speed per display panel.

3. Application Example

Application examples of the organic EL display units (display units 1 to3) described in the foregoing embodiment and Modification Examples 1 to3 are described below. The display units 1 to 3 of the foregoingembodiment are applicable to display units of electronic apparatuses inany fields that display, as an image or a picture, an image signal inputfrom outside or an image signal produced inside, such as televisions,digital cameras, notebook personal computers, portable terminal devicessuch as mobile phones, and video cameras. The display units 1 to 3described herein are particularly suitable for small-sized to mid-sizeddisplays for mobile applications. The followings show examples thereof

Application Example 1

FIG. 15 illustrates an outer appearance of a television according toApplication Example 2. The television may include, for example, an imagedisplay screen section 200 that includes a front panel 210 and a filterglass 220. The image display screen section 200 corresponds to any ofthe display units 1 to 3 according to the foregoing embodiment andModification Examples 1 to 3.

Application Example 2

FIG. 16 illustrates an outer appearance of a notebook personal computerto which the display unit 1A of the foregoing embodiment is applicable.The notebook personal computer may include, for example, a main body410, a keyboard 420 for operation of inputting characters, for example,and a display section 430 as any of the above-described display units 1to 3.

Application Example 3

FIGS. 17A and 17B illustrate an outer appearance of a tablet personalcomputer 640 according to Application Example 3. The tablet personalcomputer 640 may include, for example, a casing 620 on which a touchpanel section 610 and an operation section 630 are disposed. Any of theabove-described display units 1 to 3 of the foregoing embodiment andModification Examples 1 to 3 is mounted in the touch panel section 610.

Although description has been given of the present disclosure, referringto the embodiment, Modification Examples 1 to 3, and the applicationexamples, the disclosure is by no means limited to the foregoingembodiment, Modification Examples 1 to 3, and the application examples,and various modifications are possible.

For example, the material and thickness of each layer, the method andconditions of forming each layer are not limited to those described inthe foregoing embodiment, Modification Examples 1 to 3, and ApplicationExamples 1 to 3; each layer may be made of any other material with anyother thickness by any other method under any other conditions. Forexample, the display units 1 to 3 described in the above-describedembodiment, modification examples 1 to 3, and application examples mayuse a resin substrate such as a plastic as a substrate on which theorganic EL device 10 is provided, thus achieving a bendable display unitby taking advantage of flexibility of an organic substance.

Further, the description has been given of the case where the organic ELdisplay unit is the top surface emission (top emission) display unit inthe foregoing embodiment, Modification Examples 1 to 3, and ApplicationExamples 1 to 3; however, this is not limitative. The organic EL displayunit may also be configured to be a bottom surface emission (bottomemission) display unit. In the case of such a bottom surface emissionorganic EL display unit, the pixel electrode 26 may be made of any ofITO, IZO, and ZnO, for example. The counter electrode 29 may be made ofAl or MgAg, or the layered structure of ITO/Ag/ITO. The bottom surfaceemission organic EL display unit may be formed with a layering order inwhich the organic layers 28 are layered reversely to the foregoingembodiment.

Furthermore, the description has been given with reference specificallyto the configuration of the organic EL display device 10 in theforegoing embodiment, Modification Examples 1 to 3, and ApplicationExamples 1 to 3; however, all the layers are not necessarily provided,and another layer may also be provided. For example, a resistive layermade of a material having a resistivity of, for example, 1 to 10⁷ Ωcmmay be provided on the electron supply layer 28C. Examples of thespecific material of a resistive layer 163 may include niobium oxide(NbO_(x)), titanium oxide (TiO_(x)), molybdenum oxide (MoO_(x)), andtantalum oxide (TaO_(x)), and a mixture of niobium oxide (NbO_(x)) andtitanium oxide (TiO_(x)), a mixture of titanium oxide (TiO_(x)) and zincoxide (ZnO_(x)), and a mixture of silicon oxide (SiO_(x)) and tin oxide(SnO_(x)). The provision of the resistive layer makes it possible tosuppress the generation of a dark spot in the organic EL display unit inaddition to the effects described in the foregoing embodiment.

In addition, description has been given of the case of the active matrixdisplay unit in the foregoing embodiment, Modification Examples 1 to 3,and Application Examples 1 to 3; however, the present disclosure mayalso be applicable to a passive matrix display unit. Furthermore, theconfiguration of the pixel drive circuit that performs an active matrixdrive is not limited to those described in the foregoing embodiment; acapacitor or a transistor may also be added as necessary. In this case,a necessary drive circuit may also be added, in addition to theabove-described signal line drive circuit 120 and the scanning linedrive circuit 130, depending on alteration of the pixel drive circuit.

Description has been given of three types of pixels of the red pixel 5R,the green pixel 5G, and the blue pixel 5B as color pixels in theforegoing embodiment, Modification Examples 1 to 3, and ApplicationExamples 1 to 3. However, this is not limitative; for example, a colorpixel such as a white pixel 5W and a yellow pixel 5Y may also becombined.

It is to be noted that the effects described herein are mere examples.The effect of the technology is not limited thereto, and may includeother effects.

It is to be noted that the technology may also have the followingconfigurations.

(1)

An organic EL display unit including:

a first substrate;

a second substrate;

a display layer provided between the first substrate and the secondsubstrate, the display layer including an organic layer; and

a sealing section provided continuously from an end surface of thedisplay layer to at least a portion of respective end surfaces of thefirst substrate and the second substrate.

(2)

The organic EL display unit according to (1), wherein the sealingsection has a layered structure in which an inorganic material layer andan organic material layer are stacked in this order.

(3)

The organic EL display unit according to (1) or (2), wherein the sealingsection has a multi-layered structure in which an inorganic materiallayer and an organic material layer are stacked alternately.

(4)

The organic EL display unit according to (3), wherein

the organic material layer includes a plurality of organic materiallayers, and

the organic material layers that configure the multi-layered structurehave a width in a direction in which the first substrate, the secondsubstrate, and the display layer are stacked, the width of the organicmaterial layers becoming larger in an order of the stack of the organicmaterial layers.

(5)

The organic EL display unit according to any one of (2) to (4), whereinthe inorganic material layer contains one or more of aluminum oxide(Al2O3), silicon oxide (SiO2), zirconium oxide (ZrO2), titanium oxide(TiO2), zinc oxide (ZnO2), indium-zinc oxide (IZO), indium-tin oxide(ITO), indium-gallium-zinc oxide (IGZO), aluminum-zinc oxide (AZO),gallium-zinc oxide (GZO), silicon nitride (SiN), and silicon oxynitride(SiON).

(6)

The organic EL display unit according to any one of (2) to (4), whereinthe inorganic material layer contains one or more of ruthenium (R),platinum (Pt), iridium (Ir), palladium (Pd), rhodium (Rh), gold (Au),silver (Ag), copper (Cu), nickel (Ni), cobalt (Co), iron (Fe), manganese(Mn), tantalum (Ta), tungsten (W), molybdenum (Mo), titanium (Ti),aluminum (Al), silicon (Si), germanium (Ge), and zinc (Zn), or an alloythereof.

(7)

The organic EL display unit according to any one of (1) to (6), furtherincluding a flattening film containing an organic material and providedon the end surface of the display layer.

(8)

The organic EL display unit according to any one of (2) to (7), whereinthe inorganic material layer firstly provided on the end surface of thedisplay layer has electrical conductivity.

(9)

A method of manufacturing an organic EL display unit, the methodincluding:

forming, on a first substrate, a display layer including an organiclayer;

joining the first substrate and the second substrate together, with thedisplay layer being provided therebetween; and

forming a sealing section continuously from an end surface of thedisplay layer to at least a portion of respective end surfaces of thefirst substrate and the second substrate.

(10)

The method of manufacturing the organic EL display unit according to(9), further including providing an adhesive layer on the secondsubstrate before the joining, with the display layer being providedtherebetween, of the first substrate and the second substrate together.

(11)

The method of manufacturing the organic EL display unit according to (9)or (10), further including dividing, including the display layer, thefirst substrate and the second substrate after the joining, with thedisplay layer being provided therebetween, of the first substrate andthe second substrate together.

(12)

The method of manufacturing the organic EL display unit according to(11), wherein the dividing is performed by dicing.

(13)

The method of manufacturing the organic EL display unit according to(11), wherein the dividing is performed by scribing after removal, witha laser, of the adhesive layer provided between the display layer andthe second substrate.

(14)

An electronic apparatus with an organic EL display unit, the organic ELdisplay unit including:

a first substrate;

a second substrate;

a display layer provided between the first substrate and the secondsubstrate, the display layer including an organic layer; and

a sealing section provided continuously from an end surface of thedisplay layer to at least a portion of respective end surfaces of thefirst substrate and the second substrate.

This application is based upon and claims the benefit of priority of theJapanese Patent Application No. 2014-201517 filed with the Japan PatentOffice on Sep. 30, 2014, the entire contents of which are incorporatedherein by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations, and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. An organic EL display unit comprising: a first substrate; a secondsubstrate; a display layer provided between the first substrate and thesecond substrate, the display layer including an organic layer; and asealing section provided continuously from an end surface of the displaylayer to at least a portion of respective end surfaces of the firstsubstrate and the second substrate.
 2. The organic EL display unitaccording to claim 1, wherein the sealing section has a layeredstructure in which an inorganic material layer and an organic materiallayer are stacked in this order.
 3. The organic EL display unitaccording to claim 1, wherein the sealing section has a multi-layeredstructure in which an inorganic material layer and an organic materiallayer are stacked alternately.
 4. The organic EL display unit accordingto claim 3, wherein the organic material layer comprises a plurality oforganic material layers, and the organic material layers that configurethe multi-layered structure have a width in a direction in which thefirst substrate, the second substrate, and the display layer arestacked, the width of the organic material layers becoming larger in anorder of the stack of the organic material layers.
 5. The organic ELdisplay unit according to claim 2, wherein the inorganic material layercontains one or more of aluminum oxide (Al2O3), silicon oxide (SiO2),zirconium oxide (ZrO2), titanium oxide (TiO2), zinc oxide (ZnO2),indium-zinc oxide (IZO), indium-tin oxide (ITO), indium-gallium-zincoxide (IGZO), aluminum-zinc oxide (AZO), gallium-zinc oxide (GZO),silicon nitride (SiN), and silicon oxynitride (SiON).
 6. The organic ELdisplay unit according to claim 2, wherein the inorganic material layercontains one or more of ruthenium (R), platinum (Pt), iridium (Ir),palladium (Pd), rhodium (Rh), gold (Au), silver (Ag), copper (Cu),nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), tantalum (Ta),tungsten (W), molybdenum (Mo), titanium (Ti), aluminum (Al), silicon(Si), germanium (Ge), and zinc (Zn), or an alloy thereof.
 7. The organicEL display unit according to claim 1, further comprising a flatteningfilm containing an organic material and provided on the end surface ofthe display layer.
 8. The organic EL display unit according to claim 2,wherein the inorganic material layer firstly provided on the end surfaceof the display layer has electrical conductivity.
 9. A method ofmanufacturing an organic EL display unit, the method comprising:forming, on a first substrate, a display layer including an organiclayer; joining the first substrate and the second substrate together,with the display layer being provided therebetween; and forming asealing section continuously from an end surface of the display layer toat least a portion of respective end surfaces of the first substrate andthe second substrate.
 10. The method of manufacturing the organic ELdisplay unit according to claim 9, further comprising providing anadhesive layer on the second substrate before the joining, with thedisplay layer being provided therebetween, of the first substrate andthe second substrate together.
 11. The method of manufacturing theorganic EL display unit according to claim 9, further comprisingdividing, including the display layer, the first substrate and thesecond substrate after the joining, with the display layer beingprovided therebetween, of the first substrate and the second substratetogether.
 12. The method of manufacturing the organic EL display unitaccording to claim 11, wherein the dividing is performed by dicing. 13.The method of manufacturing the organic EL display unit according toclaim 11, wherein the dividing is performed by scribing after removal,with a laser, of the adhesive layer provided between the display layerand the second substrate.
 14. An electronic apparatus with an organic ELdisplay unit, the organic EL display unit comprising: a first substrate;a second substrate; a display layer provided between the first substrateand the second substrate, the display layer including an organic layer;and a sealing section provided continuously from an end surface of thedisplay layer to at least a portion of respective end surfaces of thefirst substrate and the second substrate.